HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Knox, A. K. Articles by Atwill, E. R. Search for Related Content PubMed PubMed Citation Articles by Knox, A. K. Articles by Atwill, E. R. GeoRef GeoRef Citation Agricola Articles by Knox, A. K. Articles by Atwill, E. R. Related Collections Surface Water Quality Biogeochemical Processes Surface Hydrology

TECHNICAL REPORTS

Surface Water Quality

Efficacy of Natural Wetlands to Retain Nutrient, Sediment and Microbial Pollutants

^a Dep. of Land Air and Water Resources, Univ. of California, Davis, CA
^b Dep. of Plant Sciences, Univ. of California, Davis, CA
^c School of Veterinary Medicine, Univ. of California, Davis, CA

^* Corresponding author (akknox132{at}yahoo.com).

Received for publication February 5, 2007. Wetlands can improve water quality through natural processes including sedimentation, nutrient transformations, and microbial and plant uptake. Tailwater from irrigated pastures may contribute to nonpoint source water pollution in the form of sediments, nutrients, and pathogens that degrade downstream water quality. We examined benefits to water quality provided by a natural, flow-through wetland and a degraded, channelized wetland situated within the flood-irrigation agricultural landscape of the Sierra Nevada foothills of Northern California. The non-degraded, reference wetland significantly improved water quality by reducing loads of total suspended sediments, nitrate, and Escherichia coli on average by 77, 60, and 68%, respectively. Retention of total N, total P, and soluble reactive P (SRP) was between 35 and 42% of loads entering the reference wetland. Retention of pollutant loads by the channelized wetland was significantly lower than by the reference wetland for all pollutants except SRP. A net export of sediment and nitrate was observed from the channelized wetland. Decreased irrigation inflow rates significantly improved retention efficiencies for nitrate, E. coli, and sediments in the reference wetland. We suggest that maintenance of these natural wetlands and regulation of inflow rates can be important aspects of a best management plan to improve water quality as water runs off of irrigated pastures.

This article has been cited by other articles:

				C. C. Hoffmann, C. Kjaergaard, J. Uusi-Kamppa, H. C. B. Hansen, and B. Kronvang Phosphorus Retention in Riparian Buffers: Review of Their Efficiency J. Environ. Qual., August 24, 2009; 38(5): 1942 - 1955. [Abstract] [Full Text] [PDF]